"...is not accessible. Network path not found" Also can't print.

I'm trying to connect a W2K PC with a Vista one, mainly to print documents.

In the "Computers near me" window on the W2K PC, the Vista PC is shown, but
I get the message: "...is not accessible. Network path not found".

I have a printer connected to the Vista PC. I can see this from the W2K PC,
and can adjust its properties, etc., but I can't print. The message is:

"Windows cannot print due to a problem with the current printer setup.
Try one or more of the following:
*Check the printer by printing a test page from Windows.
*Make sure the printer is turned on and online.
*Reinstall the printer driver. "

But this seems to be a network problem, not any of the above. (The printer
works fine from the Vista PC, and - I'm pretty sure - has worked on this
network before.)

I have found an article on the microsoft help site about the printer error,
but I'm not totally sure it applies to my situation, and I don't know which
option listed to pursue (I don't want to make things worse!).

In case it's helpful, both computers have wireless USB adapters, and both
connect OK to the internet. They're in different rooms, and it's not
practical to set up a wired connection.

(Apologies if this question has been answered earlier in this newsgroup. If
so, can you direct me there?)

TIA

JonR